Volvo C30 2007 Service And Repair Manual page 231

ACCESSORIES AND EQUIPMENT Bumpers And Mudflaps - Installation Instructions, Accessories
Get help from a colleague for this procedure.
Take the rear spoiler from the kit and press the upper part into it.
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Make sure that all catches engage.
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NOTE: Do not damage the painted surface on the upper part.
Fig. 220: Pressing In Clips For Cable Harness For Reverse Warning In Spoiler's Catches
Courtesy of VOLVO CARS CORPORATION
Applies to cars with reverse warning
Press in the clips for the cable harness for the reverse warning in the spoiler's catches.
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Fig. 221: Identifying Reflector
Courtesy of VOLVO CARS CORPORATION
Press on the reflectors from the kit on the spoiler's ends.
2012 Volvo C30 T-5